Glass Shape Speeds Drinking

FLICKR, SIMON PEARCEBeer drinkers in the United Kingdom are influenced by an optical illusion caused by the shape of a curved glass. According to a new study published this month (August 17) in PLoS ONE, certain glass shapes can actually make people down a beer more quickly, possibly contributing to the rising binge drinking problem in the U.K. that legislation has failed to control.

Different glass shapes can give the same volume of liquid the appearance of varying volumes, reasoned experimental psychologist Angela Attwood of the University of Bristol. So she and her colleagues set out to test how much glass shape affected beer drinkers’ intake. They tested 160 healthy young people, who were categorized as “social beer drinks,” not alcoholics, according to the standard WHO test for hazardous drinking. The researchers then asked each participant to drink one of two volumes of lager or soft drink—either 177 milliliters or 354 milliliters—from either a straight or curved glasses, while watching a nature documentary. At the end of each session, the participants performed a word search task, the purpose of which was merely to throw them off the true purpose of the study.

Reviewing the data, the researchers found that people drinking a full glass of beer from a curved glass drank significantly faster—in about 8 minutes, compared to the average 13 minutes it took people drinking from a straight glass. They found no differences in drinking time, however, between curved and straight glasses of half a beer.

According to Attwood, social beer drinkers naturally pace their drinking by judging how quickly they reach the halfway point. Because a curved glass holds more beer in the top half, it unconsciously motivates drinkers to speed up, reasons Attwood, who suggests a solution of marking beer glasses with a half-full line. "We can't tell people not to drink, but we can give them a little more control," she told ScienceNOW.

Comments

You don't suppose that the glass makers and pub owners are well aware of this phenomenon, and that they select glasses on this basis. Publicans have been collecting exacting data on glass-emptying rates for some centuries now.

I understand the confusion if you got the link from the "i fucking love science" facebook page as it says "The science of drinking - the shape of your glass can affect how quickly you get drunk!". Otherwise the rest are right, WTF?

I've actually found - as a "social drinker", a barworker, and the daughter of a publican - that Attwood's theory is the opposite of the case. We always use those 'flute' style glasses for half-pints, based on them getting empties faster than the mini-pint style of the same volume, and I have always seen that, when people reach the 'peak' of the inward curve (about two-third from the bottom in perpendicular height), because the glass is slimmer at the bottom than the top, it looks like there's not much left, so they tend to start necking it. I've fallen foul of this illusion myself, choking on what I assumed was a mouthful and was in fact nearly half my drink!

Added to that, when using something that looks like a companion's full-pint glass in shape, you tend to pace your drinking to match theirs on a per-drink basis, not per-volume, and so won't hit the halfway mark (1/4 pint) until they hit theirs (1/2 pint), meaning you're drinking exactly half as much as them at a steady pace; with the fluted glass, it's not so easy to subconsciously make a comparison, so in order to match pace, you need to make a conscious effort, which generally does not last longer than one or two rounds, and so you'd default to your own 'natural' pace rather than slowing down to avoid extra trips to the bar. This latter bit, I assume was not noted so much in the study, because when the social interaction and 'laziness' factors are removed, that wouldn't play so much of a part.

If this became legislation, I would recommend a "Half Empty" line instead because "Half Full" is just to much.And to be scientifically correct the glass should say "Half Empty of Liquid" as the glass is always full otherwise.

It goes down faster in this curved glass because it is 'top heavy' and if it isn't drunk faster there is the unfortunate likelihood of it spilling out both sides of ones mouth because it comes out of the glass faster when tipped (this is the sensation anyway). Whereas with a straight glass it seems to come out at a regular and non-spillable pace.

JEF AKST I hope you aren't a journalist as this piece has been written to an extremely mediocre standard,with grammatical and spelling errors. People cannot be quoted as social beer drinks? And also you use the term 'more quickly' which is incorrect English.

maybe we should stop feaking babying people and take a bit of responsibility, we don't need a marker on our glasses to show where half way is. Natural Selection is a far more efficient process without warning labels on stupidly obvious things and lines on our beer glasses.

This "research" is worthless. What kind of curve? Concave or convex? Does the radius of curvature have any effect? What about glasses with an inflection point like the Sam Adams glass? How about slanted sides, like a standard pint. Does the angle make a difference?

Coming from the thermoregulatory physiology world, I understand heat transfer fairly well. I also like to drink my beer cold. So, with a fluted glass, with a higher surface to volume ratio, it simply gets warmer faster. So, I'm just going to drink it faster. See, I have my reason, so the investigators should have asked their subjects too.